Eccentric device peristaltic pump

ABSTRACT

A peristaltic pump  30  includes a 360° backing plate  14  and  35  and an orbiter  36  for eccentrically orbiting within the backing plate. A loop of tubing  16  surrounds the orbiter  36  and is placed between the orbiter  36  and the backing plate.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to peristaltic pumps for use in surgery, especially ophthalmic surgery. More particularly, the present invention is directed to an eccentrically driven peristaltic pump.

[0003] 2. Description of the Prior Art

[0004] Peristaltic or flow-based pumps are well-known in the art.

[0005] Prior art peristaltic pumps typically consist of a series of evenly spaced rollers which engage a length of tubing. The rollers pinch the tubing against a fixed surface or stretch the aspiration tubing, such that the flow is pinched-off. The rollers or pump head continues to rotate, displacing a discrete quantity of fluid in a peristaltic fashion and in the direction of rotation. It has been said that the peristaltic pump head “milks” the fluid through the aspiration tubing via repeated compressions.

[0006] The peristaltic pump regulates aspiration flow rate by controlling the speed of the rotation of the pump head. To increase the aspiration flow rate, the speed, or numbers of revolutions per minute of the pump head is increased. Increasing the speed of the pump head causes a larger number of discrete quantities of fluid to be displaced in a given period of time. Each revolution of the pump head displaces a constant volume of fluid.

[0007] Known peristaltic pump heads typically include a plurality of rollers collectively rotatable about a central axis. Such a construction requires many moving parts. This in turn, leads to complexity and expense in the manufacturing process, as well as the potential for each moving part to break-down.

[0008] Therefore, it would be desirable to have a peristaltic pump which provides the desired even flow rate through the tubing with fewer parts, resulting in a more reliable pump.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a front elevation of a pump cartridge in accordance with one aspect of the present invention;

[0010]FIG. 2 is a partial side elevation of FIG. 1 taken along line 2-2;

[0011]FIG. 3 is a partial front elevation of a peristaltic pump in accordance with the present invention;

[0012]FIG. 4 is a side elevation of FIG. 3 taken along line 4-4;

[0013]FIG. 5 is a partial front elevation of a peristaltic pump, including surgical tubing in accordance with the present invention; and

[0014]FIG. 6 is a partial side elevation of FIG. 5 taking along line 6-6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0015] A pump cartridge 10 as shown in FIG. 1 for use with the inventive pump described in detailed below. Pump cartridge 10 includes a cartridge housing 12, such that a portion of the housing 12 forms at least a portion of a backing plate for the pump described below. In addition, the housing 12 is structured to be attached to the pump. In FIG. 1, the arcuate portion of surface 14 of the housing 12 acts as a backing plate. Cartridge 10 also includes at least a 360° loop of tubing 16. The tubing is retained by the backing plate portion via tabs 18 or other suitable mechanisms or adhesive.

[0016] As seen in FIG. 2, the backing plate or surface 14 surrounds the loop of tubing 16. Referring back to FIG. 1, fluid is pumped through tubing 16 from inlet 20 in the direction of arrow 22, and the pumped fluid exists at outlet 24 in the direction of arrow 26 to be collected in a bag or reservoir (not shown). Pump cartridge 10 requires at least a 360° loop of tubing, and preferably the 540° loop of tubing 16 shown in FIGS. 1 and 2. It will be appreciated that while a 360° loop of tubing is required for operation of the pump, more of less than the preferred 540° of looped tubing may also be used.

[0017]FIG. 3 illustrates a peristaltic pump in accordance with the present invention. Peristaltic pump 30 includes a housing 32, a 360° backing plate (formed by a combination of surface 14 and arcuate portion 34. Arcuate portion 34 is preferably attached to the housing as shown. In addition, peristaltic pump 30 includes an orbiter 36 for eccentrically orbiting within the backing plate as indicated by arrow 38. The arc of surface 35 should be centered about a center of the orbit of orbiter 36 as shown by arrow 39.

[0018] Orbiter 36 includes a centrally mounted bearing 40 that orbits in a radius about arrow 38 as indicated by dashed lines representing bearing 40.

[0019]FIG. 4 is a side elevation of the pump of FIG. 3. As seen, bearing 40 is attached to collar 42, in an off-set manner, with drive shaft 44, such that orbiter 36 will rotate or orbit in an eccentric fashion relative to arcuate portion 34 which forms a portion of the backing plate. Preferably, bearing 40 is attached to collar 42 such that orbiter 36 orbits rather than rotates. That is to say, the point indicated by arrow 46 will always remain at the top or apex of orbiter 36. This is desirable to reduce the need for lubricants between orbiter 36 and tubing 16 to reduce friction.

[0020]FIG. 3 shows orbiter 36 in its lowest-most, orbital position. In contrast, FIG. 5 shows orbiter 36 in its upper-most, orbital position. In addition, FIG. 5 shows a loop of tubing 16 surrounding the orbiter 36 and placed between the orbiter 36 and the backing plate (formed by surface 14 and surface 35). Tubing 16 has an inlet 20 and an outlet 24. Upon activation of the orbiter 36, one region of the loop of tubing 16 will be pinched (in the position shown in FIG. 5 the pinched portion corresponds with the point at arrow 46) between the orbiter 36 and the backing plate, such that the loop of tubing 16 remains pinched at all times during the eccentric orbit of the orbiter 36 within the backing plate. This causes fluid to be pumped through the inlet 20 to the outlet 24.

[0021] The cartridge housing 12 may be formed to be attached to the arcuate portion 32, which is fixedly attached to a housing 34 of the pump 30, such that the backing plate portion (surface 14) of the cartridge and the arcuate portion 34 cooperate to form a 360° backing plate. Pump cartridge 10 may be formed to attach to pump 30 by frictionally attaching to arcuate portion 34 or by any other known means, such as with a drawer or other suitable capture mechanism. While the embodiment shown discloses the 360° backing plate being formed by the joinder of cartridge 10 and arcuate portion 34, a unitary or monolithic 360° backing plate may be used. If a unitary 360° backing plate is used, it is contemplated that a cartridge would be unnecessary and tubing 16 would be simply looped around orbiter 36. Similarly, a cartridge forming the full 360° backing plate could also be used. This would simply be done by incorporating arcuate portion 34 into cartridge 10.

[0022]FIG. 6 is a partial elevation of FIG. 5 taken along line 6-6. As can be seen, orbiter 36 has tubing 16 pinched closed as seen at 48.

[0023] In operation, as orbiter 36 orbits within the backing plate, a volume of fluid is drawn from inlet 20 to outlet 24 by the pinching action. In this way, fluid and tissue can be drawn from a surgical site and deposited in a collection bag (not shown). Obviously, the higher the orbiting rate of orbiter 36, the greater the volume of fluid per unit of time that will be moved through the tubing 16. The speed of orbiter 36 is controlled by the rotation speed of shaft 44. 

I claim:
 1. A peristaltic pump comprising: a 360° backing plate; an orbiter for eccentrically orbiting within the backing plate; a loop of tubing surrounding the orbiter and placed between the orbiter and the backing plate, the tubing having an inlet and an outlet; wherein upon activation of the orbiter, one region of the loop of tubing will be pinched between the orbiter and the backing plate such that the loop of tubing remains pinched at all times during the eccentric orbit of the orbiter within the backing plate; and thereby causing fluid to be pumped from the inlet to the outlet.
 2. The pump of claim 1 wherein the backing plate is formed by a combination of a pump cartridge and an arcuate portion attached to the housing.
 3. The pump of claim 1 wherein the tubing loop forms at least a 360° loop.
 4. The pump of claim 1 wherein the tubing loop forms at least a 540° loop.
 5. A pump cartridge comprising; a cartridge housing wherein a portion of the housing forms at least a portion of a backing plate for a pump and is structured to be attached to the pump; at least a 360° loop of tubing; and wherein the backing plate portion retains and surrounds at least a portion of the loop of tubing.
 6. The pump cartridge of claim 5 wherein the cartridge housing is formed to be attached to an arcuate portion fixedly attached to a housing of the pump such that the backing plate portion of the cartridge and the arcuate portion cooperate to form a 360° backing plate.
 7. A peristaltic pump comprising: a housing; a 360° backing plate formed in the housing; an orbiter for eccentrically orbiting within the backing plate; and wherein upon activation of the orbiter, one region of a loop of tubing surrounding the orbiter will be pinched between the orbiter and the backing plate at all times during the orbit of the orbiter.
 8. The pump of claim 7 further including at least a 360° loop of tubing surrounding the orbiter.
 9. The pump of claim 8 wherein the loop of tubing and the backing plate are combined to form a pump cartridge.
 10. A pump cartridge comprising: a cartridge housing including structure forming a backing plate for a pump; attachment means for attaching the cartridge to the pump; and at least a 360° loop of tubing surrounded by and adjacent to the backing place. 